Breaking The Chain – The Role Of Intersexual Genetic Correlations In Sexual Dimorphism And The Consequences And Limits Of Their Evolution, Matthew Ma Maoloni, Tara Newman, Tristan Af Long Dr.

Theses and Dissertations (Comprehensive)

In many sexually reproducing species, males and females often differ in countless ways beyond their primary sexual organs. This phenomenon is known as sexual dimorphism, and it is generally considered to be an adaptive response to differences in the selection pressures experienced by males and females. Despite the advantages associated with sexual dimorphism, it does not evolve completely unhindered – there are plenty of biological effects that can limit the extent and rate of divergence between the sexes. This research project focusses on the potential role of the intersexual genetic correlation (r_mf­) – which describes the …

Dsrna Conjugated Phytoglycogen Nanoparticles As An Innate Immune Stimulant To Prevent Viral Infections In Rainbow Trout And Atlantic Salmon, Kayla Samms

Theses and Dissertations (Comprehensive)

Salmonids are one of the world’s most farmed fish species. These aquatic vertebrate species rely heavily on their innate immune responses to defend themselves against invading pathogens. Although commercial vaccines are available against some viral and bacterial pathogens affecting salmonids, their protective efficacy is variable. Using a prophylactic inducer of local and systemic innate immune responses could have significant implications in salmonid aquaculture. A potent inducer of the innate immune response in fish is double-stranded RNA (dsRNA), a molecule that all viruses make during their replicative cycle. Polyinosinic:polycytidylic acid (polyI:C) is a synthetic dsRNA commonly used to induce type I …

Wildlife Forage Recovery Following Boreal Wildfire, Alexis Jorgensen, Jennifer Baltzer

Theses and Dissertations (Comprehensive)

Climate change is altering the boreal wildfire regime through increases in the extent and severity of burning and reductions in fire return intervals. These changes can alter the regeneration trajectory of canopy species and ground vegetation, with implications for wildlife habitat. There is some uncertainty about the timelines of when different animal species will use burned areas as their preferred forage taxa recover following fire, and how such recovery is mediated by environmental factors. Here, we aim to address these knowledge gaps through the following questions: 1) What are the main forage types consumed by boreal wildlife and how much …

Drivers And Consequences Of Alnus Alnobetula (Green Alder) Distribution At The Taiga-Tundra Ecotone Of The Northwest Territories, Cory Wallace

Theses and Dissertations (Comprehensive)

Climate warming in the Arctic is occurring considerably faster than the global average. One of the most widespread biological responses to this warming in terrestrial systems has been a marked increase in the productivity of shrubby vegetation. Increased shrub growth and reproduction has the potential to alter both local and global aspects of ecosystem function, making understanding its drivers and environmental impact an important research priority. In this context, considerable research has focused on characterizing relationships between shrub cover, abiotic conditions, and understory communities. However, fewer studies have co-located measurements of these components simultaneously in undisturbed tundra shrub patches to …

Investigating The Antitumor Effects Of A Dsrna-Nanoparticle Complex In An In Vitro Ovarian Cancer Model, Aaron Lewis

Theses and Dissertations (Comprehensive)

An estimated 1 in 70 women will be diagnosed with ovarian cancer in their lifetime. Despite advanced detection and treatment methods, it remains a silent killer with an expected survival rate of 50%. A developing method in cancer treatment is the use of compounds that stimulate the immune system to aid in the body's fight against the disease. This project focused on the use of the potent immune stimulant double-stranded RNA (dsRNA), commercially available as polyinosinic:polycytidylic acid, poly(I:C), to induce cytotoxicity in two ovarian cancer cell lines; SKOV-3 and OVCAR-3. Some challenges exist with the delivery of dsRNA due to …

A Bioinformatic Analysis Of The Biosynthesis Of Carotenoids In The Copepod Tigriopus Californicus, Anchalya Balasubramaniam

Theses and Dissertations (Comprehensive)

Abstract

Biological pigments, also called biochromes, are coloured compounds which are displayed by a variety of life forms, including animals, due to selective colour absorption. The combination of light absorption and reflection enables each pigment to portray a distinct colour which results in the broad spectrum of colours we observe in our surroundings. Carotenoids are a large group of yellow, orange, and red biological pigments found in living organisms. Our current biomolecular knowledge of carotenoids is heavily derived from studying the pathway in photosynthetic prokaryotes, bacteria, fungi, and plants. Carotenoid pigments are exceptionally multifunctional as they act as photo-protectors against …

On The Structure And Function Of Mitochondrial Uncoupling Proteins: The Case Of Ucp2, Afshan Ardalan

Theses and Dissertations (Comprehensive)

Uncoupling proteins (UCPs) are regulated proton transporters of the mitochondrial inner membrane. UCP-mediated proton leak negatively impacts the rate of ATP synthesis. Despite the importance of their physiological role(s) in certain tissues, molecular aspects of UCPs’ structure-function relationships are not fully understood. The current study explores the tertiary and quaternary structure of UCP2, as well as its proton transport mechanism in lipid membranes. The proteins were expressed in the E. coli inner membrane, purified and reconstituted into liposomes. Proteins were characterized by semi-native SDS-PAGE. Circular dichroism spectroscopy (CD) and fluorescence quenching assays were utilized to study the conformation of proteins …

The Impact Of Combined Flexion And Compression On The Mechanical Integrity Of The Annulus Fibrosus, Keaton Briar

Theses and Dissertations (Comprehensive)

Introduction: Intervertebral disc (IVD) herniation is characterized by an expulsion of nucleus pulposus (NP) material through the annulus fibrosus (AF). The AF contains two major adhesive structures, the intralamellar matrix and the interlamellar matrix, which act to maintain the strength of the AF and prevent NP material migration. As a herniation occurs, clefts form within the intralamellar matrix, pushing the NP between adjacent collagen fibres; meanwhile, delamination of the interlamellar matrix causes the NP to pool between layers of the AF. Further, herniation more readily occurs in a combined loading scenario of both compression and flexion. Flexion, and in particular …

Exploring The Relationship Between Dog Ownership, Physical Activity, And Mental Health, Stephanie Ho, Jennifer Robertson-Wilson, Mark Eys

Theses and Dissertations (Comprehensive)

The physical and mental health benefits of regular physical activity have been well-documented (e.g., Reiner et al., 2013; White et al., 2017). Additionally, owning a dog is associated with positive health outcomes as owners are encouraged to walk. Dogs are also a source of comfort during stressful times for those in their presence (e.g., Brown & Rhodes, 2006; Westgarth et al., 2017). The aim of this study was to examine the relationship between dog ownership, physical activity, and mental health among the university student population. Over 500 university students completed questionnaires assessing their demographic information, mental health, dog ownership status, …

Physiological Impacts Of Lampricides On Invasive Sea Lamprey (Petromyzon Marinus) And Non-Target Fishes, Razvan, Adrian Ionescu

Theses and Dissertations (Comprehensive)

Parasitic sea lamprey (Petromyzon marinus) ingest large quantities of blood from fishes using their oral disc and rasping tongue, most often killing the host. In the early 1900s, sea lamprey invaded the Laurentian Great Lakes, decimating sport, commercial and culturally significant fisheries. Since the early 1960s, chemical control using the lampricides 3- trifluoromethyl-4-nitrophenol (TFM) and niclosamide have helped to reduce sea lamprey populations by 90%. Lampricides are applied to larval lamprey nursery streams targeting many generations of lamprey at once. However, there is concern about the potential adverse effects of lampricides on other fishes, particularly vulnerable lake sturgeon (Acipenser fulvescens) …

Composition And Homology In The Taxonomic Classification Of Escherichia Coli, Tanya Irani

Theses and Dissertations (Comprehensive)

As new techniques have been introduced, specifically the possibility of complete genome sequencing, better methods of defining bacterial species have also been proposed. One of the most recently proposed methods, using bioinformatic techniques, is to calculate the average nucleotide identity (ANI) between the homologous genome segments of different isolates. Another method for species discrimination that has been tested successfully is the similarity of DNA compositional signatures. However, in a recent update, DNA signatures split the available Escherichia coli complete genomes into three groups. To check if this result was consistent with such genomes belonging to different species, we tested methods …

Spinal Motor Neuron Excitability And Balance Control Changes Following Downslope Walking, Nikki Aitcheson-Huehn

Theses and Dissertations (Comprehensive)

Downslope walking (DSW) has been proposed as a rehabilitation tool for people with Multiple Sclerosis (PwMS) although there are mixed findings in young adults (YA) regarding the balance control changes, despite both populations experiencing depressed spinal motor neuron (MN) pool excitability. Our aim was to determine whether YAs could demonstrate improved balance control in conjunction with SOL H reflex depression (estimate of spinal MN excitability) following DSW. We also aimed to determine whether reciprocal inhibition was a potential mechanism for H reflex depression via conditioned SOL H reflexes. Thirty young adults (23±1.4y, 6 males) were assigned to 30-minutes of DSW …

The Nature Of Informal Roles In Interdependent Sport Teams, Jeemin Kim

Theses and Dissertations (Comprehensive)

The degree to which athletes understand and execute their formal role responsibilities (i.e., prescribed by coaches) is important for individual and group functioning (Eys, Schinke, Surya, & Benson, 2014). Recent literature suggested that informal roles can emerge within sport teams more naturally without coaches’ explicit assignments (e.g., team comedians, distracters), and have significant influences on team functioning (Cope, Eys, Beauchamp, Schinke, & Bosselut, 2011). This doctoral dissertation examined the nature of informal roles within interdependent sport teams, focusing on their antecedents and outcomes. Three separate projects were conducted. Project One examined athletes’ personality in the big five dimensions (McCrae & …

A Qualitative Investigation Into The Influence Of A Mental Health Physical Activity Intervention On University Students, Heather M. Tunks

Theses and Dissertations (Comprehensive)

Objective

Among the university student population, mental illnesses are highly prevalent. Adults aged 20-30 years have the highest rates of mood and anxiety disorders than any other age group, with approximately 12.0% diagnosed with an anxiety disorder and 7.0 to 9.0% experiencing clinical depression (Nunes et al., 2014; Pedrelli, Nyer, Yeung, Zulauf, & Wilens, 2015). Reducing or preventing the effects of mental illness among this population may have lifelong implications including improvements in coping and management of mental illness throughout the lifespan(Jaworska, DeSomma, Fonseka, Heck, & MacQueen, 2016). This research examines the lived experiences of volunteers and participants in a …

“This Is My Little World…”: Navigating The Group Exercise Experience Of Stay-Fit Members, Olivia Jones

Theses and Dissertations (Comprehensive)

Objective

Cancer is the leading cause of death in Canada, with one in two Canadians expected to develop cancer over their lifetime (Canadian Cancer Society, 2019). Exercise is reportedly a safe therapy to help ease the common side effects of cancer and its treatments (Schmitz et al., 2010). Past research has shown the benefits of group exercise while in treatment for cancer, but there is a dearth of research regarding the impact of long-term group exercise programming for cancer survivors. This phenomenological study explored the lived experiences of group exercise participation for individuals who previously had cancer and were enrolled …

Examining The Effect Of Exercise Intensity On Post-Exercise Hypotension In Middle-Aged Adults, Seth F. Mccarthy

Theses and Dissertations (Comprehensive)

Acute bouts of exercise have a transient lowering effect on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in the hours after termed post-exercise hypotension (PEH). While moderate-intensity continuous training (MICT) is effective in reducing BP acutely, little is known regarding the effects of higher intensity exercise. This study examined the effects of different exercise intensities on PEH. Six participants (females: 4; age: 48±9 y, Mean arterial pressure: 84±8 mmHg) had their BP measured before and both immediately post- (<2 h) and for 24 h following 4 experimental sessions: 1) 30 min MICT (65% V̇O_2max); 2) 20 min high-intensity interval training (HIIT; 10 x 1 min @ 90% HR_max with 1 …

Effects Of An Acute Session Of High- Vs Low-Load Resistance Training Exercise On Energy Balance, Daniel Grisebach, Derek Pd Bornath, Abigail A. Broad, Seth F. Mccarthy, Tom J. Hazell

Theses and Dissertations (Comprehensive)

This study examined the effect of an acute session of low-load high-volume resistance training versus a more traditional high-load low-volume session on energy balance (EB). Five recreationally active males (age: 24±3 y; BMI: 25.8±1.5 kgm^-2) completed three different sessions: 1) high-load (90% 1RM); 2) low-load (30% 1RM); and 3) CTRL (no exercise). Gas exchange (V̇O₂), blood lactate, and subjective appetite perceptions were measured before each session, as well as at 0, 1, and 2 h post-exercise. Delayed onset muscle soreness (DOMS) in the quadriceps, pectorals, hamstrings, deltoids, and latissimus dorsi was measured at 24 and 48 …

Investigation Of Rna Interference (Rnai)-Mediated Gene Silencing In Rainbow Trout, Sarah Au

Theses and Dissertations (Comprehensive)

RNA interference (RNAi) was first characterized in plants and invertebrates as an antiviral innate immune response. It is a natural antiviral defence mechanism to degrade viral RNA by virus-induced gene silencing. Studies showed synthetic long double-stranded RNA (dsRNA; >30bp) degraded Caenorhabditis elegans messenger RNA (mRNA) transcripts, resulting in sequence-dependent gene silencing. Currently, there is only limited research on RNAi in fish, particularly the use of long dsRNA to trigger sequence-specific gene silencing. This is because studies have shown long dsRNAs trigger interferon response that could mask gene-specific RNAi effects. This thesis explored long dsRNA-mediated RNAi pathways in rainbow trout cells …

Can Zooplankton On The North American Great Plains ‘Keep Up’ With Climate-Driven Salinity Change?, Mariam Elmarsafy

Theses and Dissertations (Comprehensive)

The Great Plains of North America are projected to become more arid as the climate changes over the next century. Salinity levels for lakes in this region are linked to climate, suggesting that lakes will become more saline as the climate becomes drier. One group of organisms that might be affected by increased salinity levels are the zooplankton, aquatic invertebrates that transfer energy from primary producers to macroinvertebrates and fish. Little is known about the ability of zooplankton to adapt to long-term increases in lake salinity levels. For my thesis, I used resurrection ecology to examine how a common zooplankter, …

Effects Of Phosphorus On Mycorrhizal Colonization Of Wetland Plants Under Natural And Controlled Conditions, Miriah Tucker

Theses and Dissertations (Comprehensive)

An important symbiotic relationship that forms in wetland environments occurs between plants and arbuscular mycorrhizal fungi (AMF). In terrestrial communities AMF colonization is limited by phosphorus; excessive phosphorus can lead to an uncoupling of the relationship. Few studies have examined the relationship between AMF and phosphorus concentration in wetland plants. The studies that have, found a decrease in AMF colonization at phosphorus concentrations as low as 0.03 mg/L P, however, methodological issues limit the interpretation of these results. To address this, a field and greenhouse study were completed using more realistic exposure conditions, field deployable assays (FDA), and natural intact …

The Effects Of Dorsal Lateral Telencephalon Lesions On Zebrafish Social Behaviour, Hailey Katzman

Theses and Dissertations (Comprehensive)

Zebrafish are extremely social and aggregate in groups to form shoals. This social behaviour has been studied in the wild and in a laboratory setting, yet the mechanisms underlying the behaviour are unknown. There is evidence to suggest that the dorsal lateral telencephalon might play a role in shaping shoaling behaviour, being involved in modulating social behaviours and social reward associated with shoaling. In the current thesis, I adapted and combined several existing methods for performing lesions on the dorsal lateral telencephalon to create my own method to measure the role of the dorsal lateral telencephalon in social reward and …

Synthesis And Biophysical Analysis Of The Cell-Penetrating Peptide Penetratin And Its Aromatic Analogues, An Le

Theses and Dissertations (Comprehensive)

Cell-penetrating peptides (CPPs) interact with biological membranes, undergo cellular intake/uptake, and may act as potential drug delivery agents. Understanding the molecular interactions of these peptides with membranes contributes to gaining a better knowledge of their potential use in medical and pharmaceutical applications to improve human health. The current research focuses on understanding the mechanisms of a CPP in interaction with different model phospholipid membranes. The peptide penetratin (primary sequence: RQIKIWFQNRRMKWKK) is an example of a CPP that can interact with and pass through biological membranes. The current thesis provides spectroscopic and calorimetric evidence that penetratin associates with lipid membranes. Circular …

Functional Characterization Of Proteins From A Putative Chondroitin Sulfate A Degrading Operon And The Crystal Structure Of An Exo-N-Acetylgalactosamine-4-Sulfatase From Tannerella Forsythia, Peter Nguyen

Theses and Dissertations (Comprehensive)

Advanced periodontitis has been shown to have strong associations with the residence of a bacterial triad of Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola also known as the red complex. These bacteria were previously thought to be asaccharolytic, making them better suited to survive in deep in periodontal pockets where access to carbohydrates from food is limited. Information gathered from genomic analysis suggested that upregulation of an operon (BFO2285-BFO2295, BFO3043) could confer the capacity for T. forsythia to degrade chondroitin-4-sulfate, the principle glycosaminoglycan of alveolar bone tissue. Bioinformatics analysis suggested the operon was similar to an operon found in Bacteroidetes …

Hydrogen Peroxide: A Grower’S Best Friend?, Mitchell Eicher-Sodo

Theses and Dissertations (Comprehensive)

Hydrogen peroxide (H₂O₂) is an oxidizing agent used to disinfect irrigation systems (e.g. nutrient solution and equipment) used in controlled environment plant production and produces no harmful by-products. The action of H₂O₂ is non-selective, and therefor H₂O₂ will oxidize all components of the irrigation water as well as tissues from the greenhouse crops being irrigated. The phytotoxic effect H₂O₂ has on common greenhouse crops is not well understood, requiring detailed characterization and determination of threshold concentrations. Thresholds within the thesis were based on applied H₂O …

Using Phytoglycogen-Based Nanoparticles To Enhance Inosine Monophsophate Delivery Using Rainbow Trout And Bovine Models, Kristof Jenik

Theses and Dissertations (Comprehensive)

Recently, there has been interest in the use of nucleotides in industrials feeds, with inosine monophosphate showing the most promising effects on growth and immunity. Rainbow trout and Alberta cattle are two of Canadas most profitable farmed animals, if their growth rates and immunity could be enhanced this would further improve their value. The impacts of IMP, a phytoglycogen-based nanoparticle (NP) and inosine monophosphate cationically bound to the phytoglycogen-based nanoparticle (IMP-NP) were characterized in rainbow trout in vivo and in vitro and in vitro in bovine cells. Rainbow trout that were fed an IMP-NP containing feed on average had higher …

Structural And Functional Characterization Of Cazyme And Cazyme-Related Proteins From: Bacteroides Thetaiotaomicron And Porphyromonas Gingivalis: Two Abundant Colonizers Of The Human Microbiome, James Stevenson

Theses and Dissertations (Comprehensive)

The human body consists of approximately 30 trillion cells, while non-human microbes that reside on and within the body outnumber human somatic cells by a factor of 1.3 – 2.3. The interplay between our cells and those of the colonizing microorganisms affect physiology in a multitude of ways, both beneficial and detrimental. Microbes found in the oral cavity, such as the Red Complex member Porphyromonas gingivalis, are associated with pathology, namely periodontal diseases including gum deterioration, tooth decay, and loss of underlying alveolar bone. At the other end of the gastrointestinal tract, microbes such as Bacteroides thetaiotaomicron are found …

Influence Of Salinity On Copper-Ligand Formation Constants, Fatimah Barnawi

Theses and Dissertations (Comprehensive)

Natural Organic Matter (NOM) is known to reduce metal, such as copper, toxicity in aquatic environments. Copper is essential for organisms, but elevated concentrations of dissolved copper can potentially be toxic. The toxicity of copper is related to its bioavailability, which is influenced by toxicity modifying factors, such as NOM (quantified as Dissolved Organic Carbon (DOC) in mg C/L), alkalinity, pH and major cation and anion concentrations. The principles are the same for fresh and saltwater, but the influence of high salt concentrations, such as in estuaries, and associated activity corrections, can modify NOM complexation of metals (i.e., modify logK …

Boreal Subarctic Lake Water Quality, Zooplankton Communities, And Benthic Macroinvertebrate Communities In Areas Impacted By Wildfire, Thomas J. Pretty

Theses and Dissertations (Comprehensive)

Wildfires are a natural phenomenon in the boreal forest, but recent studies suggest that there will be increases in the frequency and severity of fires in this region over the next century. When wildfires occur in lake catchments, they may affect water quality and invertebrate communities living in associated lakes. Invertebrates, including zooplankton and benthic invertebrates, play important roles in aquatic food webs, acting as conduits of energy from primary producers to larger organisms such as fish and water birds. Therefore, it is important to understand how these groups will respond to changes caused by fires. Unfortunately, few studies have …

What Makes An Image Memorable? Effects Of Encoding On The Mechanism Of Recognition, Asiya Gul

Theses and Dissertations (Comprehensive)

Memory is undoubtedly one of the most important processes of human cognition. A long line of research suggests that recognition relies on the assessment of two explicit memory phenomena: familiarity and recollection. Researchers who support the Dual Process Signal Detection (DPSD) model of recognition memory link the FN400 component (a negative ERP deflection peaking around 400 ms at frontal electrodes) with familiarity; however, it is currently unclear whether the FN400 reflects familiarity or implicit memory. Three event-related potentials (ERP) studies were conducted to determine whether implicit memory plays a role in setting up encoding strategies, and how these encoding strategies …

Assessing Threats And Mitigation For Scarlet Ammannia (Ammannia Robusta) In Southwestern Ontario, Kayla Salive

Theses and Dissertations (Comprehensive)

Scarlet Ammannia (Ammannia robusta) is an annual emergent wetland plant of the Lythraceae family. Throughout most of its distribution, the species population is stable under present conditions. However, this is not the case in Canada, where A. robusta is considered endangered with only a few small populations documented in British Columbia and Ontario. In response, a recovery strategy was created for A. robusta outlining the lack of information on the species biology and ecology, with a primary objective to assess the populations in Ontario and gain information on what may be contributing to the species rarity. To assess …